Hyponatremia-Adult

Definition

Hyponatremia is a potentially serious condition in which the level of sodium in the blood is too low. An imbalance is created when there is too little sodium for the amount of water in the body. As a result, water moves into the body’s cells causing them to swell.

There are different types of hyponatremia, each resulting in low sodium in the body:

Euvolemic hyponatremia—water level increases, but sodium level stays the same

Hypervolemic hyponatremia—water and sodium levels increase, but the water gain is greater

Hypovolemic hyponatremia—water and sodium levels decrease, but the sodium loss is greater

Causes

Hyponatremia may be caused by:

Syndrome of inappropriate antidiuretic hormone secretion
(SIADH)—Antidiuretic hormone signals the kidneys to absorb more water, reducing urine output. In SIADH, the mechanism that stops antidiuretic hormone from collecting water is impaired. This impairment results in excess water in the body.

Sweating—In people with
cystic fibrosis
, excess sodium is excreted through sweat. It may also occur in people with severe
burns
when electrolytes and fluids are not replaced.

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor will ask you about your fluid intake and do some tests.

Tests may include:

Blood tests—to check the sodium level in your blood, and the functioning of your organs

Urine test—to check the sodium level in your urine

Other tests may be done to look for any underlying causes of your hyponatremia.

Treatment

Treatment may depend on:

What is causing the low sodium level

How long the sodium level has been low

How low the sodium level is

Your level of hydration

In cases when the sodium has been low for more than 1-2 days, your doctor will want to correct the sodium level slowly. Serious complications may occur when sodium levels rise too rapidly. It can be corrected more quickly if it has been lw for a short time.

Treatment options may include:

Restricting fluid intake

Identifying the underlying cause and getting proper treatment

Medications to help remove extra fluid from your body

IV fluids to deliver sodium restore proper balance

Prevention

To help reduce your chance of hyponatremia:

If participating in sports, drink only as much water as you need to quench your thirst. Sport drinks that provide electrolytes, such as sodium, along with water may be helpful during endurance events.

Work with your doctor to effectively manage any conditions that you may have.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.